1986 IET | Alldatasheet

Document overview

  • Manufacturer or author: Provided By alldatasheet.com(free datasheet download site)
  • PDF pages: 2

Technical content

IET LABS, INC. in the Gen Rad Tradition www.ietlabs.com TEL: (516) 334-5959 • EMAIL: info@ietlabs.com Omnical Sound Level Calibrator

1986 Page 1 of 2

1986 Catalog May 2023

Features:

  • Capable of tes ng all the basic characteris cs of virtually any sound level meter
  • Mul ple levels: 74, 84, 94, 104, 114 dB re 20 µPa
  • Mul ple frequencies: 125, 250, 500, 1000, 2000 and 4000 Hz.
  • Calibrated tone bursts for fast and slow responses
  • Crest factor capability
  • Analog output
  • Ba ery operated The 1986 is designed to permit checking nearly all the characteristics of a sound level meter as specifi ed by IEC and ANSI standards. With its supplied and optional microphone cavity adapters, it can be used with all types and sizes of commonly used measurement microphones. The calibrator generates tones at six diff erent frequencies, from 125 Hz to 4 kHz in octave steps, and diff erent sound pressure levels, from 74 to 114 dB in 10 dB steps. This allows a sensitivity check of an acoustic instrument near the specifi c frequency and level of each measurement being made. The frequency response of an overall sound-measuring system, weighting network or fi lter may also be checked. The two sources of linearity error in a sound measuring instrument are easily checked with the 1986. One source is the indicator scale (meter or digital display) and the other source is the level range control. The 1986 is designed to permit checking of nearly all characteris! cs of a sound level meter as specifi ed by IEC and ANSI standards.

1986 Omnical Sound Level Calibrator

The multi-level output of the 1986 allows selection of diff erent levels on a sound measuring system and a check of the instrument's response at each level. Standards require that Fast detector response be tested by applying a sinusoidal signal having a frequency of 1 kHz and a duration of 200 ms. Slow detector response is tested by applying a sinusoidal signal having a frequency of 1 kHz and a duration of 500 ms. The 1986's tone burst mode allows checking to the above requirements by automatically presenting a 1 kHz sinusoidal signal of either 200 ms or 500 ms duration. The 1986 permits a check of rms accuracy and crest factor capability by presenting repeated tone bursts with a high crest factor. The transducer on the 1986 is resiliently mounted to protect against damage from the accidental bumps and drops often encountered in fi eld calibration situations. The entire assembly, except for the test cavity, is enclosed in a molded plastic case that is tightly sealed against dust and moisture. The cavity of the 1986 is designed to fi t GenRad 1" microphones, the WE 640AA and Tokyo Riko MR 130. An adaptor is included to accommodate GenRad 1/2 inch microphones. An optional 1986-9700 adaptor set allows you to use the 1986 on instruments with Bruel & Kjaer 1", ½” and ¼” microphones, the Shure Brothers ⅛" microphone, and the ⅜" microphone on GenRad's 1954 Noise Dosimeter.

IET LABS, INC. in the Gen Rad Tradition www.ietlabs.com TEL: (516) 334-5959 • EMAIL: info@ietlabs.com Omnical Sound Level Calibrator

1986 Page 2 of 2

Output sound-pressure levels: 74, 84, 94, 104, or 114 dB re 20 µPa Nominal output frequencies: 125, 250, 500, 1000, 2000 or 4000 Hz Actual output frequencies: Preferred per ANSI S1.6-1960 and ISO R266: 125.9, 251.2, 501.2, 1000, 1995 or 3981 Hz ±3%. Reference conditions: Temperature: 20°C (68°F) Atmospheric pressure: 1013 mbar (760 mm of Hg) (30 in. of Hg) Relative humidity: 65% Microphone eff ective volume: 0.5 cm3 (0.03 in.3 ) (nominal for GR 1961 Electret-Condenser Microphone) Accuracy of sound-pressure Level: Understated reference environmental conditions; 114 dB SPL all frequencies, except 4 kHz , for cavity alone or when used with any adaptor (except 1 ⅛" adaptor): ±0.25 dB 114 dB SPL at 4 kHz: ±0.5 dB At output levels other than 114 dB SPL, tolerance is increased by: ±0.1 dB ⅛" adaptor: ±0.5 dB at 1 kHz only Temperature coeffi cient of sound-pressure level: Less than ±0.02 dB/°C for all frequencies except 4000 Hz Tone-burst signals: Test signals provided as prescribed by ANSI S1.4-1971; IEC Publications 123-1961. 179-19 73 and 179A-1973;and Consolidated Revision of IEC Publica tions 123 and 179. In tone burst modes,output can be either continuous (SET FAST/SLOW or SET CREST FACTOR) or series of bursts (FAST, SLOW or CREST FACTOR), as selected. Level is uncalibrated and continuously adjus table. In FAST or SLOW, peak amplitude of tone burst is identical to that of continuous signal. In CREST FACTOR, rms value of tone burst sequence is identical to that of continuous signal. FAST: repeated tone bursts at 1 kHz, 200 ms duration every 2 s, for measuring sound level meter FAST rise response;amplitude is contin uously variable from 72 dB to 118 dB re 20 µPa; back- ground level is 20 dB below burst level. SLOW: repeated tone bursts at 1 kHz, 500 ms duration every 10 s, for measuring sound-level-meter SLOW rise response; amplitude is continuously variable from 72 to 118 dB re 20 µPa; background level is 20 dB below burst level. CREST FACTOR : repeated tone bursts at 2 kHz, 5.5 ms duration, 40-Hz repetition rate, crest factor 3, for measuring rms detector-indicator accuracy and amplifi er crest-factor capacity ; rms amplitude is contin uously variable from 75 to 111 dB re 20 µPa. Variable sound-pressure-level control: Enabled only in tone-burst modes. Provides 11 dB of adjustment Electrical output: Output provided from nominal 600 Ω shortable source. Voltage proportional to sound pre ssure; 230 mV ±30 mVrms nominal output corresponding to 114 dB SPL Distortion: <1% THD acoustical or electrical Power: Powered by 9 V alkaline battery; battery provides at least 8 h continuous operation Battery test: Internal circuitry checks condition of battery continu ously with automatic instrument shutdown when battery voltage falls below acceptable range Microphone coupling: Transducer cavity accommodates following 1" microphones: GenRad 1961 electret-condenser, and GenRad 1971 ceramic Temperature: Operating: -10°C to +50°C (+14°F to +122°F) Storage: -40°C to +70°C (-40°F to +140°F), with battery removed Humidity: 0% to 90% R.H. non-condensing, operating Dimensions: (wxhxd): Approximately 280 x 67 x 165 mm (11 x 2.625 x 6.5 in.) Weight: Approximately 1 kg (2.2 lb) STANDARD MODELS 1986-9700 Omnical Sound Level Calibrator Includes: Instruction Manual

9 V battery

½” adapter 1987-7061 1986-9600 Carrying Case

ORDERING INFORMATION

1987-9600 Calibrator Adapter Set; includes adapters for Bruel and Kjaer 1", ½” and ¼” microphones and others